Erik Pasche

Urban flood management.

1. Introduction Andras Szollosi-Nagy & Chris Zevenbergen 2. Land use & urban floods in developing countries Carlos Tucci & Adolfo Villanueva 3. Cities, lakes and floods: the case of the Green Hyderabad Project, India Joep Verhagen 4. Co-operation within Europe on flood management and spatial planning Roelof Moll 5. Spatial measures and instruments for flood risk reduction in selected EU countries - a quick scan Willem Oosterberg & Jasper Fiselier 6. Risk perceptance and preparedness and flood insurance Paul Baan 7. The role of private insurance companies in managing flood risks in the UK and Europe David Crichton 8. New strategies of damage reduction in urban areas proned to flood Erik Pasche & Timm Ruben Geissler 9. Flood resilience in the built environment: damage and repair Stephen Garvin 10. California climate change: hydrologic response, and flood forecasting Norman Miller Conclusions Andras Szollosi-Nagy & Chris Zevenbergen

Advances in urban flood management

* Challenges in Urban Flood Management Chris Zevenbergen & Berry Gersonius * Sustainable Measures for Flood Attenuation - Sustainable Drainage and Conveyance Systems SUDACS Joachim T. Tourbier & Iain White * Characterisation of Urban Streams and Urban Flooding Ian Douglas, Mira Kobold, Nigel Lawson, Erik Pasche & Iain White * Flood Modelling in Urban Rivers - The state-of-the-art and Where to go Erik Pasche * Urban Flood Management - Simulation Tools for Decision Makers Peter Oberle & Uwe Merkel * Flood Frequency Analysis for Extreme Events Felix Frances & Blanca A. Botero * A Critical Review of Probability of Extreme Rainfall: Principles and Models Demetris Koutsoyiannis * Role of Detention and Retention Basins in Stormwater Management and Environmental Protection Miodrag Jovanovic * Flood Induced Indirect Hazard Loss Estimation Models William Veerbeek * Flood Damage Estimation and Flood Risk Mapping Andreas Kron * Flood Risk Modelling in Urban Watercourses - Results of the European FLOWS Project Erik Pasche & Nicole von Lieberman * Flood Repair Standars for Buildings Stephen L. Garvin & David J. Kelly * Economic feasibility study of flood proofing domestic dwellings Chris Zevenbergen, Berry Gersonius, Najib Puyan & Sebastiaan van Herk * Local flood defence systems in Europe Mitja Brilly * European Flood Strategies in Support of Resilient Buildings David J. Kelly & Stephen L. Garvin * FloReTo - Web Based Advisory Tool for Flood Mitigation Strategies for Existing Buildings Natasa Manojlovic * New Approaches to Flood Risk Management - Implications for Capacity-Building Joanne Tippett & Emma J. Griffiths * Towards Integrated Approaches to Reduce Flood Risk in Urban Areas Richard Ashley, John Blanksby, Jonathan Chapman & JingJing Zhou * Hydrological Modelling of Floods Mira Kobold * An Overview of Flood Protection Barriers Jean-Luc Salagnac * An Innovative Semi-Permanent Flood Protection Structure - Alternative to Sandbags and Supplements to Conventional Earth Embankments Jarle T. Bjerkholt & Oddvar G. Lindholm * The English Planning System and Flood Risk Management Juliet Richards * French Regulations for Urban Flood Management Nicolas-Gerard Camphuis

Integration of resiliency measures into flood risk management concepts of communities

Based on the recent flood events in Europe and following the latest scientific reports on climate change IPCC, and urban development EEA it becomes evident that the areas in Northern and Middle Europe are becoming increasingly affected by flooding. In the changing environment, the conventional flood protection measures are not providing sufficient protection level and are very cost intensive. New strategies to cope with flooding have to be developed and implemented to adapt the communities to climate change in an adequate way. This paradigm shift from “flood fighting” to “living with floods” reflects the current EU Flood Policy formulated in the EU Flood Directive and adopted by national laws. Especially vulnerable are urban areas where the economic growth, in case of extreme flood events, can be irreversibly disrupted. Other than applying mere conventional protection, the innovative resilience concepts should be considered that integrate the building environment into flood protection by improving the resilience performance of the urban fabric and build capacity of stakeholders. In order to optimise the performance of flood protection, as alternative to resiliency measures for each household separately, integrative solutions for the area/ city quarter are to be considered. In general, which level of integration is to be implemented depends technical, economic and socio-political criteria. The adopted integration level can in any case be supported by the adhock measures that can serve as an intermediate solution and initial phase for active stakeholder involvement. For the historic area of the City of Lauenburg that was recently severely affected by flood events of the river Elbe (2002, 2006), resilience concepts have been developed. Without a solution for flood protection, sustainable development of the city, primarily focused on tourism, cannot be achieved. Different resilience solutions, based on different levels of integration and adaptability are presented and discussed.

On the Way to a Flood Risk Management Plan

The Flood Directive EC 2007/60 specifies the structure and objectives of the flood risk management plan and the favourable mitigation measures to be taken for reducing the risk. However, little information is given about the strategy to develop and implement this management plan on a local level. There is an obvious need to find a good governance concept which best supports the implementation process and which will lead to acceptance and proper application of the new paradigm in flood risk management. Within the INTERREG IVb project SAWA (http://www.sawa-project.eu/) the authors have developed and implemented a participatory planning approach for the implementation of a flood risk management plan according to EC FD, which tries to meet the requirements of good governance through broad stakeholder involvement in the planning process. It uses Learning and Action Alliances (LAA) as a communication and decision making platform in which public and professional stakeholders can develop the plan together in a four-step cycle of awareness raising, understanding, experimenting, and evaluation. The software tool KALPYPSO Planer-Client, developed within SAWA, can be regarded as a corner stone in this decision-making process. It enables professional and public stakeholders to define their own scenarios of drivers, flood mitigation and adaptation measures, and to evaluate the impact and efficiency of these scenarios. This new governance approach will be demonstrated with a real case study—the Wandse urban catchment, Hamburg—and the results and experiences will be discussed.

A Hybrid Meshing Scheme Based on Terrain Feature Identification

Hydrodynamic engineering makes profitably use of numerical simulations which rely on discrete element meshes of the topography. To cope with specific circumstances in river hydraulics, the presented hybrid meshing scheme comprises following proposals: river beds and areas of significant terrain slopes are meshed with regular elements to support user specified edge ratio and element orientation representing flow gradients appropriately; floodplains are represented as irregular triangle meshes, concatenating disconnected regular meshes while warranting high approximation quality. Automatic breakline detection approximates flow relevant changes in topographic gradients and defines borders of different mesh types. This paper presents an enhanced strategy for a terrain feature analysis based on b-spline analysis grids and on an interpolation scheme for breakline points in order to reduce the zigzag property of detected breaklines. This scheme for terrain analysis and meshing functionality is implemented in the open source software tool HybridMesh.

Processing Remote Sensing Data for Flood Hazard Assessment

In environmental engineering numerical simulations are essential for analyses, forecasts and decisions. Usually, numerical simulations in hydrodynamics are based upon the finite element or the finite differences method. The quality of these numerical simulations depends strongly on the approximation accuracy of the topography. In addition, the efficiency of the mesh generation plays a decisive role for the applicability of a numerical simulation method. Nowadays, the generation of these meshes make use of high resolution topographic survey data, such as LiDAR (light detection and ranging), InSAR (interferometric synthetic aperture radar) or echo sounding bathymetry. These survey campaigns deliver a tremendous amount of data, needing to be analysed with regard to significant terrain features. The authors present a breakline identification tool for floodplains using a slope classifying approach. The detected breaklines are used for a hybrid meshing approach. This approach is based on a Delaunay refinement for the floodplains and a freeform surface approximation technique for the river bed. Accuracy and efficiency of this hybrid mesh generation approach are verified for an application in flood hazard assessment. The area under consideration is located in a typical part of the North German lowlands. The River Stoer is characterised as alluvial, partly straightened stream and is a tributary of the River Elbe.

A Data Mining Approach for Capacity Building of Stakeholders in Integrated Flood Management

New approaches to managing flood events are increasingly of more relevance due to recent widespread floods and the presumed changes in the climate. These approaches fall under the integrated flood management (IFM) banner and focus not only on flood prevention, but on flood resilience. This paper introduces an application (FLORETO) for IFM that utilizes the data mining approach, in a web based three tier system, devoted to the capacity building of stakeholders as a micro-scale resilience strategy of IFM. The intelligent models, which constitute the business logic in FLORETO, are used to match the input parameters or design criteria, describing properties prone to flooding, to technically justifiable flood mitigation measures. Datasets from the German city of Kellinghusen were collected and intelligent models were built. Satisfactory results have been obtained, which shows the promise of this data mining approach and opens the door for its application for IFM in other regions.